Mr. G. B. So\rerby on Pentatrematites. 457 



Tab. Suppl. XXXIII, fig. C. 

 a. Small bones or arms in the Ambulacra. 

 h. Ridges to which the bones a are affixed. 

 c. The ridges removed, leaving a striated surface. 



Pentatrematites pentangularis. 

 P. oblonga, supernfe latior, quinquangularis, ambulacris brevibus, angulis 

 obtusis. 

 Syn, Platycrinites pentangularis, Miiller, (the arms being imaginary 

 in his figure). 



Tab. Suppl. XXXIII, fig. 7. 

 I regret that it is not in my power, owing to the length of time that has 

 elapsed since the descriptions of former species were drawn up, to point 

 out more in detail the distinguishing characters of these species ; I cannot 

 however doubt that by careful attention to the plate and the characters 

 above described, every difficulty will be removed. 



References to Tab. Suppl. XXXIII. 

 Fig. 1. Pentatrematites angulata. Zool. Journ., vol. IV., p. 89. 



a. Lateral view. 



b. Base. 



2. Pentatrematites infiata, two views taken fronts different spe- 



cimens. Zool. Journ., vol. IV., p. 90. 



3. Pentatrematites oblonga. Zool. Journ,, vol. IV., p. 90. 



4. Pentatrematites oblonga, var. 



5. Pentatrematites orbicularis. 



a. Lateral view. 



b. Apex. 



6. Pentatrematites acuta, two views. 



7. Pentatrematites pentangularis. 



